This application claims the priority of German patent application 102 00 759.4, filed 10 Jan. 2002, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a system for the dynamic destination routing of vehicles.
European Patent Document EP 0 838 797 A1 discloses a destination routing system for a vehicle, in which a first (static) route is computed without considering traffic information. The destination routing is then started for the first route and, during the drive, received traffic information is analyzed with respect to its relevance to the first route. If relevant traffic information occurs for the first route, a second (dynamic) route is computed, considering traffic information. The second route is offered for selection to the driver as an alternative route, if the computed driving time is shorter on the alternative route than on the first route. Selection of the alternative route is performed by driving the alternative route.
German Patent Document DE 199 56 108 A1 discloses a method for dynamic destination routing of a motor vehicle, in which, when traffic hindrances occur on an originally computed route, alternative routes are computed for several turn-off points, bypassing the traffic hindrance. The alternative routes are offered to the driver for his selection. The driver may choose an alternative route by using his operating unit, by driving the alternative route, in which case the system automatically recognizes which of the suggested routes is driven by the driver. The driver then receives destination routing information with respect to the recognized alternative route.
One object of the invention is to increase the driver's acceptance of a system for the dynamic destination routing of vehicles, of the initially mentioned type.
This and other objects and advantages are achieved by the system according to the invention, which analyzes additional information, particularly traffic information, of several information sources and matches this information. These information sources comprise RDS (Radio Data System), RDS/TMC (Radio Data System/Traffic Message Channel), control-center-supported services, internet-based and/or WAP-based (Wireless Application Protocol) services. In this manner, a destination routing can be carried out dynamically on the basis of data from multiple sources, which increases the currency and the reliability of the method. As a result of the match, it can also be ensured that all additional information supplied to the driver is in itself without contradiction.
During the drive, the destination routing system constantly performs a type of self-diagnosis in order to determine whether the issued recommendations make sense (that is, whether they remain optimal) in view of actual conditions. To increase the acceptance by the driver, it is advantageous to supply explanatory information to the driver on the basis of the check of whether the routing makes sense.
For checking whether the routing makes sense, it is compared, for example, whether the actual parameters correspond to the parameters determined when defining the optimal route or used as a basis for the optimal route. In an advantageous embodiment of the invention, a constant comparison is made during the drive of whether the actual driving progress (that is, in the form of the actually covered path and/or the time which has passed since the start of the drive) corresponds to the driving progress computed when determining the optimal route. This constant comparison is advantageous for ensuring that the information offered to the driver by the destination routing system is free of contradictions with respect to his or her direct on-site perception. This is especially relevant when using predicted additional information, particularly traffic predictions. When the prognosticated traffic event does not occur, this can be determined by the comparison between the actual driving progress and the purported driving progress.
When the actual parameters deviate from the determined parameters of the optimal route, further measures can be taken to increase the quality of the destination routing and/or to increase the acceptance by the driver. Thus, other, more detailed additional information can be requested which may help to clarify the deviation or the taking of new measures. This might include, for example, information which explains the deviation and informs the driver that a search is taking place for an alternative route.
For the purpose of judging whether the route recommendation makes sense, it is also advantageous to take into account the fact that different information sources may exist for the additional information. The sources for additional information, which are simultaneously available, may differ with respect to the quality of the information (for example, the correctness, currency or quantity of the information, including the completeness and/or the depth of details). The method takes these differences into account during the analysis and the matching.
It is also advantageous to supply the driver with explanatory information concerning, for example, the source of the additional information that is taken into account in the destination routing, with an assessment of its qualitative and/or quantitative characteristics. Such information enables the driver to understand the situation and the information on which the destination routing information is based. In the event of apparent mistakes of the destination routing, this increases the acceptance by the driver.
In an advantageous further development of the invention, to determine whether the route recommendation makes sense, it is checked during the drive whether relevant additional information is available and/or is arriving for the residual route to be driven, including externally received additional information and/or information present in a memory carried along in the vehicle. The details of the additional information are constantly verified. Thus, during the drive, new additional information may actively be requested. For example, when a local traffic jam is approached during the drive, new additional information will be actively requested, specifically detailed and updated additional information concerning the traffic jam located ahead of the vehicle, so that a precise response can be made based on the existing updated and detailed additional information.
If new aspects occur during the drive (for example, the real parameters deviate from the determined parameters of the optimal route and/or that the additional information concerning the route situated in front of the vehicle changes) a dynamic computation of the residual route is triggered (that is, the route from the current location of the vehicle to the destination).
Further, the acceptance by the driver can be increased if when caught in a traffic jam, for example, he or she receives an explanation as to why no alternative route was selected. As a result, it is possible for the driver to eliminate contradictions between the actions of the destination routing and his own additional information, such as obtained from his direct perception of the local traffic situation.
The destination routing system comprises two system parts. The first system part is fixedly installed in the vehicle and comprises a computer, a memory, particularly for storing a digital map, an input unit and an output unit. The second system part is constructed to be portable and comprises a memory, particularly for storing additional information; a computer; a receiving unit, particularly for receiving additional information; and a computer. The second system part may be constructed as a PDA, as a PDA-type unit, as a laptop, as a portable mobile phone. It may also be constructed as a unit so that one or more units are integrated in a housing or several units can be fitted together.
The static destination routing, which is based on data stored in a digital card, is implemented on the system part fixedly installed in the vehicle. The static destination routing takes into account no dynamic additional information. The dynamic destination routing is carried out on the portable system part, where the dynamic additional information is taken into account.
This arrangement permits a novel division of functions between static process steps, which take place on system parts fixedly installed in the vehicle, and dynamic process steps which take place on portable system parts which can be connected with the vehicle. These system parts, which can be connected with the vehicle, can be easily exchanged. They can also be pre-recorded with new software versions; and can therefore easily be changed even after the delivery of the vehicle. This is advantageous for implementation of processes and options for dynamic determination of the destination routing, which are subjected to constant changes, particularly with respect to the offered traffic data and their utilization. The functional division of the system into parts installed in the vehicle and portable parts simplifies the further development of dynamic functionalities and facilitates lower expenditures.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.